The board that runs Jackson Health System on Monday voted to ask Miami-Dade commissioners to call a special election in November asking voters to approve an $830 million bond to pay for renovations and equipment upgrades at the taxpayer-owned hospital system.

The request from the Public Health Trust that runs Jackson came as something of a surprise, since it was not on the agenda prior to the meeting, but was added at the last minute by Darryl Sharpton, the board’s newly appointed chairman.

Though the resolution approved by the board did not mention a specific dollar amount, Sharpton said the hospital system needs a cash infusion of between $700 million and $1 billion to improve facilities, which include the main hospital in Miami’s civic center and satellite hospitals in North Miami Beach and South Miami-Dade. A spokesman for Jackson said the amount requested would be $830 million.

“We’re at a crossroads,’’ Sharpton said at Monday’s meeting of the seven-member board. “We have to do something drastically different or risk being irrelevant.’’